From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx124.postini.com [74.125.245.124]) by kanga.kvack.org (Postfix) with SMTP id 5FE746B0070 for ; Mon, 12 Nov 2012 18:43:43 -0500 (EST) Date: Mon, 12 Nov 2012 23:43:41 +0000 From: Christoph Lameter Subject: Re: [PATCH 0/8] Announcement: Enhanced NUMA scheduling with adaptive affinity In-Reply-To: <20121112160451.189715188@chello.nl> Message-ID: <0000013af701ca15-3acab23b-a16d-4e38-9dc0-efef05cbc5f2-000000@email.amazonses.com> References: <20121112160451.189715188@chello.nl> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Paul Turner , Lee Schermerhorn , Rik van Riel , Mel Gorman , Andrew Morton , Andrea Arcangeli , Linus Torvalds , Ingo Molnar , Thomas Gleixner On Mon, 12 Nov 2012, Peter Zijlstra wrote: > The biggest conceptual addition, beyond the elimination of the home > node, is that the scheduler is now able to recognize 'private' versus > 'shared' pages, by carefully analyzing the pattern of how CPUs touch the > working set pages. The scheduler automatically recognizes tasks that > share memory with each other (and make dominant use of that memory) - > versus tasks that allocate and use their working set privately. That is a key distinction to make and if this really works then that is major progress. > This new scheduler code is then able to group tasks that are "memory > related" via their memory access patterns together: in the NUMA context > moving them on the same node if possible, and spreading them amongst > nodes if they use private memory. What happens if processes memory accesses are related but the common set of data does not fit into the memory provided by a single node? The correct resolution usually is in that case to interleasve the pages over both nodes in use. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org